It's all Greek to me :)
Anyway -- I wonder how many words there are for "rock" in the Aramaic, because in the Hebrew there are two main words for "rock" -- the Hebrew "tsur" and "cela" -- both massive rocks that can be used as foundations or strongholds.
But Jesus did not use those words for Peter's surname. Instead he called him "Cephas" -- "Keepa" in Aramaic from "keph" in Hebrew which means "a hollow rock".
A hollow rock is certainly not something that you would use as the foundation of your church [although many churches are built over grottos].
[although many churches are built over grottos].
;-)
Where are you getting this derivation? Any Hebrew cognate of this word is interesting, but you can't use that cognate as evidence to supersede the meaning it actually has in Aramaic.
To wit, if you go to Jimmy Akin's site, you'll see this very issue of "hollow rock" is discussed.
Forget about the apologetic stuff there for the moment, and just skip down to the center of the thread, where you'll see a scan Jimmy has from "A Compendious Syriac Dictionary" by R. Payne Smith. Syriac is of course a dialect of Aramaic.
Take a look at the definitions there that are given for Kepha: stone, rock, stone vessel, column, idol, grindstone, whetstone, millstone, etc. Nothing there about hollowness. You could probably make a case for a vessel being a hollow stone. But there are plenty more meanings where you can't....whoever heard of a hollow grindstone or millstone?